heavy dom bardment is reported today in the suburbs in the surrounding area. rebel leaders called the airport a legitimate target and gave a stark warning to the regime and outside travelers to avoid it at all costs. fighting near the airport forced the suspension of commercial flights this week. some airlines have already stopped all together. a rebel takeover of the airport would also cut off weapon supplies and allies like iran says andrew tabler of the washington institute near east policy. >> as the country's longest runways, from that location that jets from iran land, carrying a lot of sophisticated weapones, so knocking that location out. taking it over and holding it would allow the rebels to begin their push towards damascus without having the threat of resupply from the iranians. >> reporter: that makes it far too valuable for forces loyal to syrian president bashar al-assad to give up without a fight. the battle for damascus and its airport might prove to be the bloodiest in more than 20 months of syria's brutal civil war. charlie d'agata, cbs news